Commit 0667059d authored Feb 21, 2020 by Murphy Zhou Committed by Steve French Mar 22, 2020

cifs: allow unlock flock and OFD lock across fork

Since commit d0677992 ("cifs: add support for flock") added
support for flock, LTP/flock03[1] testcase started to fail.

This testcase is testing flock lock and unlock across fork.
The parent locks file and starts the child process, in which
it unlock the same fd and lock the same file with another fd
again. All the lock and unlock operation should succeed.

Now the child process does not actually unlock the file, so
the following lock fails. Fix this by allowing flock and OFD
lock go through the unlock routine, not skipping if the unlock
request comes from another process.

Patch has been tested by LTP/xfstests on samba and Windows
server, v3.11, with or without cache=none mount option.

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/flock/flock03.c


Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Pavel Shilovsky <pshilov@microsoft.com>

parent c7e9f78f

fs/cifs/smb2file.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -152,6 +152,11 @@ smb2_unlock_range(struct cifsFileInfo cfile, struct file_lock flock,
		(li->offset + li->length))
		continue;
		if (current->tgid != li->pid)
		/*
		* flock and OFD lock are associated with an open
		* file description, not the process.
		*/
		if (!(flock->fl_flags & (FL_FLOCK \| FL_OFDLCK)))
		continue;
		if (cinode->can_cache_brlcks) {
		/*

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